Per OCE, if Hunter did use funds from his committee, he may have violated House, rules, standards of conduct and federal law.

The ethics committee in December decided to continue its own review of the matter.

Elliot Berke and Gregory Vega, attorneys for Hunter, said in a statement that Hunter last year "became aware of expenditure issues confronting his campaign committee."

"Out of an abundance of caution, he took corrective action in consultation with the FEC and, ultimately, he and his wife personally repaid the campaign approximately $60,000," the statement said.

Hunter intends to cooperate fully with the government on the investigation, according to Berke and Vega. Additionally, he "maintains that to the extent any mistakes were made they were strictly inadvertent and unintentional."

"Rep. Hunter has shown a blatant disregard for the rules, spending tens of thousands of dollars from his campaign for his personal benefit," Noah Bookbinder, the group's executive director, said in a statement. "This is the most egregious Congressional spending scandal since Aaron Schock. We are glad to see the Office of Congressional Ethics voted unanimously for an investigation and will be closely following the FBI’s criminal investigation in Congressman Hunter."